Yahoo Web Search

... may be that it can never be seen - at least not in the visible light spectrum . Astronomers have witnessed all the steps leading...

...solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum . Solar radiation includes visible light, ultraviolet light, infrared, radio...

...em waves encounter matter.  Just a question of which portion of the wave spectrum (light spectrum or radio spectrum , energy spectrum ) the particular matter will mostly affect.